It's the opposite for me. I personally trust the opinion of a critic more than the general public who will often like any crap if it has a high budget. I also think they are spot on about Vanilla Sky.
Well, I'd never trust the critics - it's all hollywood politics and business with those guys, as they all run in the same circles.
You agree with their vanilla sky rating, but many others don't - I've met loads of people, and read lots of reviews, that say it's a fantastic film.
Everybody has different taste, and perceptions of what is good, or not, which kind of ties in with the point of the thread - only you can make that decision for yourself.